1. Field of the Invention
The present invention relates to a planetary gear device for use in an automatic transmission of an automobile, and more particularly, to a planetary gear device in which a washer is configured to ensure the lubricating oil can be smoothly supplied to frictional regions between a pinion gear and a carrier.
2. Description of the Related Art
Generally, a planetary gear device is used to change the speed of power output from an engine to thereby transmit the power to an output shaft. The planetary gear device includes a long-pinion gear, a plurality of short-pinion gears meshed with the outer circumference of the long-pinion gear, and a ring gear meshed with the outer circumference of the short-pinion gears. The center of the long-pinion and short-pinion gears is rotatably supported by means of carriers.
Typically, the carriers are mounted on a shaft with washers press fit on the shaft inside the carriers. The washers have oil passages. However, conventional washers typically allow for the flow of the lubricating oil only in one direction. They therefore suffer from a reduced supply of lubricating oil, and are difficult in commercialization due to their complicated assembling operations.